u_int16_t group_num; /* number of this queue */
u_int16_t flags;
u_int8_t copy_mode;
+ struct rcu_head rcu;
};
-static DEFINE_RWLOCK(instances_lock);
+static DEFINE_SPINLOCK(instances_lock);
static atomic_t global_seq;
#define INSTANCE_BUCKETS 16
struct nfulnl_instance *inst;
head = &instance_table[instance_hashfn(group_num)];
- hlist_for_each_entry(inst, pos, head, hlist) {
+ hlist_for_each_entry_rcu(inst, pos, head, hlist) {
if (inst->group_num == group_num)
return inst;
}
{
struct nfulnl_instance *inst;
- read_lock_bh(&instances_lock);
+ rcu_read_lock_bh();
inst = __instance_lookup(group_num);
- if (inst)
- instance_get(inst);
- read_unlock_bh(&instances_lock);
+ if (inst && !atomic_inc_not_zero(&inst->use))
+ inst = NULL;
+ rcu_read_unlock_bh();
return inst;
}
+static void nfulnl_instance_free_rcu(struct rcu_head *head)
+{
+ kfree(container_of(head, struct nfulnl_instance, rcu));
+ module_put(THIS_MODULE);
+}
+
static void
instance_put(struct nfulnl_instance *inst)
{
- if (inst && atomic_dec_and_test(&inst->use)) {
- kfree(inst);
- module_put(THIS_MODULE);
- }
+ if (inst && atomic_dec_and_test(&inst->use))
+ call_rcu_bh(&inst->rcu, nfulnl_instance_free_rcu);
}
static void nfulnl_timer(unsigned long data);
struct nfulnl_instance *inst;
int err;
- write_lock_bh(&instances_lock);
+ spin_lock_bh(&instances_lock);
if (__instance_lookup(group_num)) {
err = -EEXIST;
goto out_unlock;
inst->copy_mode = NFULNL_COPY_PACKET;
inst->copy_range = NFULNL_COPY_RANGE_MAX;
- hlist_add_head(&inst->hlist,
+ hlist_add_head_rcu(&inst->hlist,
&instance_table[instance_hashfn(group_num)]);
- write_unlock_bh(&instances_lock);
+ spin_unlock_bh(&instances_lock);
return inst;
out_unlock:
- write_unlock_bh(&instances_lock);
+ spin_unlock_bh(&instances_lock);
return ERR_PTR(err);
}
static void __nfulnl_flush(struct nfulnl_instance *inst);
+/* called with BH disabled */
static void
__instance_destroy(struct nfulnl_instance *inst)
{
/* first pull it out of the global list */
- hlist_del(&inst->hlist);
+ hlist_del_rcu(&inst->hlist);
/* then flush all pending packets from skb */
- spin_lock_bh(&inst->lock);
+ spin_lock(&inst->lock);
+
+ /* lockless readers wont be able to use us */
+ inst->copy_mode = NFULNL_COPY_DISABLED;
+
if (inst->skb)
__nfulnl_flush(inst);
- spin_unlock_bh(&inst->lock);
+ spin_unlock(&inst->lock);
/* and finally put the refcount */
instance_put(inst);
static inline void
instance_destroy(struct nfulnl_instance *inst)
{
- write_lock_bh(&instances_lock);
+ spin_lock_bh(&instances_lock);
__instance_destroy(inst);
- write_unlock_bh(&instances_lock);
+ spin_unlock_bh(&instances_lock);
}
static int
size += nla_total_size(data_len);
break;
+ case NFULNL_COPY_DISABLED:
default:
goto unlock_and_release;
}
int i;
/* destroy all instances for this pid */
- write_lock_bh(&instances_lock);
+ spin_lock_bh(&instances_lock);
for (i = 0; i < INSTANCE_BUCKETS; i++) {
struct hlist_node *tmp, *t2;
struct nfulnl_instance *inst;
__instance_destroy(inst);
}
}
- write_unlock_bh(&instances_lock);
+ spin_unlock_bh(&instances_lock);
}
return NOTIFY_DONE;
}
for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
if (!hlist_empty(&instance_table[st->bucket]))
- return instance_table[st->bucket].first;
+ return rcu_dereference_bh(instance_table[st->bucket].first);
}
return NULL;
}
static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
{
- h = h->next;
+ h = rcu_dereference_bh(h->next);
while (!h) {
if (++st->bucket >= INSTANCE_BUCKETS)
return NULL;
- h = instance_table[st->bucket].first;
+ h = rcu_dereference_bh(instance_table[st->bucket].first);
}
return h;
}
}
static void *seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(instances_lock)
+ __acquires(rcu_bh)
{
- read_lock_bh(&instances_lock);
+ rcu_read_lock_bh();
return get_idx(seq->private, *pos);
}
}
static void seq_stop(struct seq_file *s, void *v)
- __releases(instances_lock)
+ __releases(rcu_bh)
{
- read_unlock_bh(&instances_lock);
+ rcu_read_unlock_bh();
}
static int seq_show(struct seq_file *s, void *v)